Tonight (7th July 2010) marks a historic moment as a solar-powered aircraft makes an overnight flight using only the power generated in its solar panels throughout the day. This is the first time the Solar Impulse project will have tried this, but if it works then this will mark a real breakthrough in aviation technology.

Pilot Andre Borschbergwill take the prototype to an altitude of 8,500 meters (27,900 feet) this evening and slowly descend throughout the night with the aim of landing at dawn.

At the time of writing, the aircraft had just set off. There will be regular updates on the progress of the flight through the Solar Impulse website where you can see views from the aircraft, a view of the cockpit and the aircraft’s route across the project’s home of Switzerland and a 3D animation so that you can view what the pilot will be able to see. Apparently he will be able to see the moon and get a good view of planet Venus along with a spectacular sunset and sunrise (if the flight is successful).

The aircraft weighs the same as a family car but it’s wingspan is about as long and wide as a normal passenger plane as this is where its solar panels are mounted. It will travel at a slow and continuous speed of 23 knots which is the best speed to keep in flight while using the least amount of energy.

This experimental aircraft and venture is being sponsored by Bertrand Piccard, who was the first to circle the globe non-stop in a balloon.

The next live press briefing will be midnight Swiss time, which is GMT +2 which will be broadcast on the website. In the meantime there is live footage of the aircraft in flight.